Composite roll for manufacturing heat transfer tubes and method of manufacturing composite roll for manufacturing heat transfer tubes

摘要

In a composite roll (1) for manufacturing heat transfer tubes that has two or more grooving rolls (2-5) having protrusions where at least one of cross sectional shapes, lead angles relative to a rotation direction and sizes is different, by coaxially combining the rolls (2-5) to form multiple types of grooves on a surface of metallic strips by pressing against the metallic strips, the composite roll (1) for manufacturing heat transfer tubes of the present invention is characterized in that the two or more grooving rolls (2-5) are joined in one body in a mutually surface contacting state. It is also preferable that the two or more grooving rolls (2-5) are joined by diffusion bonding.